1 /* $OpenBSD: ex_z.c,v 1.8 2015/03/29 01:04:23 bcallah Exp $ */
2
3 /*-
4 * Copyright (c) 1993, 1994
5 * The Regents of the University of California. All rights reserved.
6 * Copyright (c) 1993, 1994, 1995, 1996
7 * Keith Bostic. All rights reserved.
8 *
9 * See the LICENSE file for redistribution information.
10 */
11
12 #include "config.h"
13
14 #include <sys/types.h>
15 #include <sys/queue.h>
16
17 #include <bitstring.h>
18 #include <limits.h>
19 #include <stdio.h>
20 #include <stdlib.h>
21 #include <string.h>
22
23 #include "../common/common.h"
24
25 /*
26 * ex_z -- :[line] z [^-.+=] [count] [flags]
27 * Adjust window.
28 *
29 * PUBLIC: int ex_z(SCR *, EXCMD *);
30 */
31 int
ex_z(SCR * sp,EXCMD * cmdp)32 ex_z(SCR *sp, EXCMD *cmdp)
33 {
34 MARK mark_abs;
35 recno_t cnt, equals, lno;
36 int eofcheck;
37
38 NEEDFILE(sp, cmdp);
39
40 /*
41 * !!!
42 * If no count specified, use either two times the size of the
43 * scrolling region, or the size of the window option. POSIX
44 * 1003.2 claims that the latter is correct, but historic ex/vi
45 * documentation and practice appear to use the scrolling region.
46 * I'm using the window size as it means that the entire screen
47 * is used instead of losing a line to roundoff. Note, we drop
48 * a line from the cnt if using the window size to leave room for
49 * the next ex prompt.
50 */
51 if (FL_ISSET(cmdp->iflags, E_C_COUNT))
52 cnt = cmdp->count;
53 else
54 cnt = O_VAL(sp, O_WINDOW) - 1;
55
56 equals = 0;
57 eofcheck = 0;
58 lno = cmdp->addr1.lno;
59
60 switch (FL_ISSET(cmdp->iflags,
61 E_C_CARAT | E_C_DASH | E_C_DOT | E_C_EQUAL | E_C_PLUS)) {
62 case E_C_CARAT: /* Display cnt * 2 before the line. */
63 eofcheck = 1;
64 if (lno > cnt * 2)
65 cmdp->addr1.lno = (lno - cnt * 2) + 1;
66 else
67 cmdp->addr1.lno = 1;
68 cmdp->addr2.lno = (cmdp->addr1.lno + cnt) - 1;
69 break;
70 case E_C_DASH: /* Line goes at the bottom of the screen. */
71 cmdp->addr1.lno = lno > cnt ? (lno - cnt) + 1 : 1;
72 cmdp->addr2.lno = lno;
73 break;
74 case E_C_DOT: /* Line goes in the middle of the screen. */
75 /*
76 * !!!
77 * Historically, the "middleness" of the line overrode the
78 * count, so that "3z.19" or "3z.20" would display the first
79 * 12 lines of the file, i.e. (N - 1) / 2 lines before and
80 * after the specified line.
81 */
82 eofcheck = 1;
83 cnt = (cnt - 1) / 2;
84 cmdp->addr1.lno = lno > cnt ? lno - cnt : 1;
85 cmdp->addr2.lno = lno + cnt;
86
87 /*
88 * !!!
89 * Historically, z. set the absolute cursor mark.
90 */
91 mark_abs.lno = sp->lno;
92 mark_abs.cno = sp->cno;
93 (void)mark_set(sp, ABSMARK1, &mark_abs, 1);
94 break;
95 case E_C_EQUAL: /* Center with hyphens. */
96 /*
97 * !!!
98 * Strangeness. The '=' flag is like the '.' flag (see the
99 * above comment, it applies here as well) but with a special
100 * little hack. Print out lines of hyphens before and after
101 * the specified line. Additionally, the cursor remains set
102 * on that line.
103 */
104 eofcheck = 1;
105 cnt = (cnt - 1) / 2;
106 cmdp->addr1.lno = lno > cnt ? lno - cnt : 1;
107 cmdp->addr2.lno = lno - 1;
108 if (ex_pr(sp, cmdp))
109 return (1);
110 (void)ex_puts(sp, "----------------------------------------\n");
111 cmdp->addr2.lno = cmdp->addr1.lno = equals = lno;
112 if (ex_pr(sp, cmdp))
113 return (1);
114 (void)ex_puts(sp, "----------------------------------------\n");
115 cmdp->addr1.lno = lno + 1;
116 cmdp->addr2.lno = (lno + cnt) - 1;
117 break;
118 default:
119 /* If no line specified, move to the next one. */
120 if (F_ISSET(cmdp, E_ADDR_DEF))
121 ++lno;
122 /* FALLTHROUGH */
123 case E_C_PLUS: /* Line goes at the top of the screen. */
124 eofcheck = 1;
125 cmdp->addr1.lno = lno;
126 cmdp->addr2.lno = (lno + cnt) - 1;
127 break;
128 }
129
130 if (eofcheck) {
131 if (db_last(sp, &lno))
132 return (1);
133 if (cmdp->addr2.lno > lno)
134 cmdp->addr2.lno = lno;
135 }
136
137 if (ex_pr(sp, cmdp))
138 return (1);
139 if (equals)
140 sp->lno = equals;
141 return (0);
142 }
143